Automatic casinghead equipment



July 30, 1935. F. w AH4|LD v 21,009,888

AUTOMATIC CASIG HEAD EQUIPMENT v Filed July 28, 1930 A s sheets-sheet 1July 30, 1935.

F. w. HILD AUTOMATIC CASING HEAD EQUIPMENT Filed July J28, 1950 3Sheets-Sheet 2 aww 324%@ M/Q'/ F. W. HILD AUTOMATIC CASING HEADEQUIPMENT July so,l 1935.

s sheets-sheet s Filed July 28, 1950 Patented July 30, 1935 y l UNITEDSTATES PATENT OFFICE 15 Claims.

My invention relates to the control and prey vention of iiuid blow outsfrom wells.

It is an object of my present invention to provide equipment which shallautomatically function to prevent escape of the well fluid upon theearliest manifestation of unstable iiuid conditions in the well casing.

Another object of my invention is to provide an automatic casing valvewhich shall close automatically upon withdrawal of the drill from thecasing.

Another object of my invention is to provide a blow out prevented in thecasing valve for cooperation with the drill string.

Another object is to provide an automatic mud valve which shallautomatically close the well outlets upon change of specific gravity ofthe uid passing through the valve and/or upon change of the iluid leveland/or upon change of the rate of the fluid flow.

Another object is to provide for concentrically disposed wellcasings-terminal collars having vent heads and vent pipes atsubstantially the same common level.

Certain other features of my present invention are improvements of thosedisclosed in my co-pending applications Serial No. 382,384, filed July3l, 1929, now Patent No. 1,938,020 and Serial No. 385,270, led August12, 1929, now Patent No. 1,906,265.

Other objects and advantages of my invention will be apparent from thefollowing descriptions and the accompanying drawings:

Figure l is a vertical elevation of the apparatus embodying myinvention.

Figure 2 is a vertical section of Figure l.

Figure 3 is a vertical section of the automatic mud valve.

Figure 4 is a vertical section taken on the line 5 4 of Figure 3.

Figure 5 is an end view of the mud valve outlet.

Figure 6 is a horizontal part section taken on the line `S--li of Figure2.

Figure 'l shows in vertical section another view of the automatic casingvalve showing the valve gate in intermediate and closed positions.

Figure 8 is a horizontal plan view in part section taken on the line 8 8of Figure 2.

Figure 9 is a horizontal View in part section of the casing valve.

Figure l0 is a vertical elevation in part section of -the casing valve.

vFigure 1l is a view in part vertical sectionl showing the springs andpistons for closing the gate of the casing Valve.

(Cl. 16B-15) Figure 12 is a diagrammatic View of the moving parts of thecasing valve.

Referring to the drawings, the casings l5, I6, l1 and i8 are threadedinto and suspended from casing terminal collars I9, 20, 2i and 22respectively which in turn rest upon foundation 23. The automatic casingvalve 25 is secured to the casing terminal collars by flange collar 24.The

main or axial outlet of the casing valve contains the axial blowoutpreventer 26 through which the kelly or drill stem 21 extends; a splitsocket wrench 28 is engaged by the rotary machine 29 for tightening orfreeing the preventer 26 in the casing valve 25. The automatic mud valve30 is connected by the pipe 3| to a lateral outlet of the casing valve25.

Terminal collar i9 is seated in and contained by terminal collar 20;likewise collar 20 is seated in terminal collar 2l which in turn isseated in and contained by terminal collar 22. Packings 3i supplementthe tight fits between the termiral collars in providing iluid tightjoints between the casings. In order to control fluid which mightaccumulate between the strings of casings, channels leading to suitablevent heads are formed in the outer terminal collars, none being neededfor the innermost collar when it is for the final, or oil string. Thuschannels 32 extend to vent heads 33 of terminal collar 20, and into thevent heads are threaded the usual vent pipes 34 which have hand operatedvalves (not shown). In like manner terminal collar 2| has channels 35,vent heads 3B and vent pipes 31. Outermost terminal collar 22 haschannels 38, vent heads 39 and vent pipes 40,

Flange collar 24 is threaded fluid tight into the innermost terminalcollar i9 and is also secured by bolts 4l to the outermost casingterminal collar 22, thereby adding the force exerted by the bolts to theforce due to the heavy weight of the suspended casings in rmly seatingeach terminal collar in the adjacent containing collar so as to lockthem all together solidly as a unit. The ange collar 24 Ahas the thread42 for receiving the Christmas Tree pipe assembly for flowing well or atubing head for pumping. Obviously when the innermost string of casingis the oil string and therefore the final string, the flange collar andthe oil string terminal collar can be one piece instead of two.

The casing valve 25 is secured fluid tight to the flange collar 24 inany suitable manner as by tongues and grooves 44 and bolts 43. Thecasing valve body 45 has a lateral outlet 46 to which the automatic mudvalve 30 is connected and another lateral outlet 41 which is keptnormally closed by a hand valve (not shown) This outlet 41 is used toadmit mud fluid or to draw oil well fluid under certain conditions ofdrilling or bringing in the well. Into the main or axial outlet of thecasing valve body 45 is firmly secured the v'alve bushing 48 the underface of which forms the valve seatA 49 and against which the valve gate59 automatically swings to close the axial outlet when the valve bodydoes not contain pipe or the drill string. The valve gate 50, circularin form, has a central pin l which is engaged by the trunnion arm52. Thecentral pin 5| may rotate loosely in the trunnion arm so as to permitthe valve gate 50 to adjust itself into good closing contact with valveseat 49. For convenience of assembly the trunnion arm 52 is in two partsbolted together and is pivoted in the valve body 45 by the trunnion pins53 which are held in place by the blind plugs 54. The trunnion arm 52has crank pinsI 55 against which force may be exerted to swing thetrunnion arm upwardly or downwardly and thereby close or open the casingvalve 25.`

Upward movement is by one or both of two forces, one force being that ofa pair of springs which always act to automatically close the casingvalve. The other force is by any suitable pressure such as by the mudpump, or steam, or the water supply system of adequate pressure. Twocylindrical holes 55 bored in the valve body 45 contain the hollowpistons 51. Within each piston is sleeve 58 containing the helicalspring 59 which resting on the inner bottom of the piston, acts alwaysto force the sleeve 58 upwardly against crank pin 55. The cylinders 56at their lower ends communicate with uid channel 60 which in turncommunicates with inlet 8|. This inlet is controlled by a suitabletriple valve 62 which connects with the mud pump or other iluid pressuresupply. The triple valve also controls the discharge opening 63 whichpermits fluid to drain from the cylinders 56 and from fluid channel 60into the well casing. A twoway valve, the same as triple valve 52 hasbeen described and illustrated in detail in my copending applicationSerial No. 384,213 for Automatic blowout preventer, filed August 7,1929. Rotating the triple valve 62 in one direction admits iiuid underpressure to cylinders 55 and forces the pistons 51 upward against crankpins 55, this force being additional to the force of the springs 59 forclosing the valve gate 50. Movement of the triple valve 62 in theopposite direction shuts off the fluid supply and opens dischargeopening 63 draining the fluid from the cylinders 56 into the well casingwhereupon the pistons 51 will move down to their bottom positions.

The cylinders are closed at the top by blind plugs 54 through one ofwhich the casing valve stem 65 is threaded. The valve stem 65 may berotated downward against a crank pin 55 to force and hold open valvegate 50. Reverse rotation of the stem backs it against its seat in blindplug 64 thus efectivelypreventing leakage past the threads of stem 65. Asecond means for holding open the valve gate is provided by the ring 86which rests upon a ledge 81 in the valve body 45. The inner bore of thering is less than the diameter of the drill bit 68 but suiciently largeto freely pass the tool joints or couplings and the protectors. Justbefore threading the bit into the drill collar of the drill string, thering 66 is placed on the drill collar above the bit, and when the bit islowered through the valve 25, the ring encounters the ledge 61. Thevalve stem 65 is thenbacked oli permitting the springs 59 to force thevalve gate 50 against the ring 66. On coming out the hole the ascendingbit 68 intercepts the ring 66 and carries it upward, whereupon thesprings 59 automatically close the valve gate 50 against its seat 49.Should there also be upward movement of the Well fluid, this too willact to force the valve gate upward into its seat, and the well fluidpressure will be added to that of the springs in maintaining closure ofthe casing valve 25.

The valve bushing 48 has external thread 69 for receiving locking nutlll. The upper end of the locking nut forms the outer half of breechlock 1| An upwardly extending lug 12 of the valve body 45 has anadjustable set screw 13 for limiting unscrewing of the locking nut fromvalve bushing 48. A ring 14 projecting from the locking nut 18intercepts the set screw 13 for this purpose.

The axial blowout preventer 26 may be assembled on the kelly 21 andlowered therewith into bushing 48 of casing valve 25 and may rest uponring 66. A tapered plug has a central opening for snug sliding t on thcdrill stem, and has outwardly the form of a truncated cone. The plugconsists of packing 16 which may be of rubber moulded on to two metalpieces, one the plug top 11 and the other the plug bottom 18. The plugis journaled in the taper bored preventer shell i9 the outer lower partof which is threaded to receive the retaining ring 80 and also the jamring 8| for locking the retaining ring in position. The retaining ringhas an annular projection which limits the downward movement of the plugl5 and upon which the plug may rotate. Upward movement of the plug isrestricted by the taper bore of the preventer shell 19. When the plug ismoved upward as by lifting the drill stem 21 or by pressure of the wellfluid, the rubber packing 16 is forced against the taper bore whichcauses compression of the rubber inwardly so that it packs more tightlyagainst the drill stem. When extremes of pressure are encountered, theplug top 11 and the plug bottom 18 which are made of metal, are alsoforced against the taper bore of shell 19. The upper portion 82 of shell`i9 is a hollow cylinder in form and has an outwardly projectingshoulder 83. An-inward ledge 84 on the bushing 48 intercepts shoulder83, so that il ring 56 be omitted, downward movement of the blowoutpreventer 26 is nevertheless limited and it cannot fall through into thewell. An annular packing ring 85 of rubber or like material is formed onthe portion 82 and rests upon the shoulder' 83. Resting upon and inposition to press down upon the packing ring 85 is locking member 86which at its upper outer portion consitutes the inner mate to the breechlock 1| of the locking nut 1D. The upper inner portion of the lockingmember 85 is hexagonal in form to rcceive the hexagonal socket wrench29.

The socket wrench 28 is of two parts hinged together so that the wrenchmay be placed' around the kelly and lowered' into the hexagonal socketof locking member 86. Upon rotating this socket wrench as by the rotarymachine 29, the

locking member 86 will first be rotated into locking engagement withbreech lock 1l and continued rotation will screw the locking nut 'ldownward carrying with it the locking member 86. This will exertdownward pressure on the packing ring 85 forcing it tightly againstshoulder 83 of shell 19 and against the walls of valve bushing 48 andcylindrical portion 82 of the shell 19 thus effectively preventing theescape of the fluid past the outside of the preventerZS and rmly lockingthe preventer into the casing valve 25.

The automatic mud valve 30 has the body 81 containing two compartmentsone for the specie gravity Valve 88 and the other for the flow levelvalve 89. A cover plate 90 encloses the two compartments except forvalve inlet 9| and valve outlet 92. Between the two compartments isopening 99 which is the outlet for the specific gravity valve 88 and theinlet for ow level valve 89. The specific gravity gate 94 is of wood orother material which will oat in ordinary mud fluid but which will sinkwhen the specic gravity of the mud fluid is diminished as by waterdilution or gas. The valve gate 94 swings on pln 95, the ends of whichare securedin blind holes in `thc body 31 and the cover plate 99.

The flow level Valve gate 9G is outside hung by reason of its lever arm91 which swings on pin 98, the pin being secured to body 81 outside andabove the valve outlet 92. The valve gate 96 has limited movement aboutpin 99 of the lever arm 91 so that the valve gate may be self-adjustingwhen against its valve seat at outlet $2. Hung on the same pin- 98 ispilot gate |09 which normally closes outlet 92 when no liquid flowsthrough it. When however liquid begins to flow through the valve andfrom outlet 92, the pilot gate |99 swings outwardly and actuates asignal such as an electric buzzer to indicate flow and converselycessation of flow. As the flow level in the valve rises the flowultimately encounters the valve gate 96 and acts to swing the gate toclose the valve. A counter balance arm serves to diminish the requiredpressure for swinging the valve gate. Both the valve lever arm 91 andthe pilot gate |90 are provided with jaws on their adjacent faces at thepin 98; these jaws intercept when the pilot gate swings out to asuilicient angle with respect to the lever arm 91 so that the pilot gateassists the valve gate 96 in effecting closure of the automatic mudvalve.

A pipe |92 controlled by hand valve |03 is threaded into the top of.specific gravity valve compartment 88. Likewise a pipe |04 controlled byhand valve |85 is threaded into the top of flow level valve compartment89. .The two pipes are for several purposes: Thus pipe |92 may serve asan air vent when mud uid rises in specic gravity valve compartment 88;or it may be used to draw uid from the well casing; or it may admit mudfluid or the like to close the specific gravity valve gate 94 and toreplenish the mud supply in the casing. Pipe |84 may admit mud fluid toclose the flow level valve gate 96 and to open valve gate 94, and alsoto replenish the mud supply in the well.

When the casing valve 25 has been closed whether by the hydraulicpistons 51, the springs 59 or by the well fluid pressure-it may berequired to hold the Valve gate 59 firmly closed and relieve the pistonsand the springs of this duty. Such a means is shown in Figure '7; athreaded hole in the center of valve gate 5U receives the threaded endof stem or handle EDG to- Which is secured circular plate |01 which tsinto valve bushing 48 and is forced by the handle |06 tightly onto ashoulder |08 of said bushing.

Considering the operation of the apparatus it should be noted that theoutlet 92 of the automatic mud valve 30 is at a higher level than thetop of taper plug 15, so that the plug rotates inthe mud fluid whichserves as its lubrication.

When the mud fluid ceases' to flow from outlet 92, whether because ofautomatic closure of either of the two valve gates in the mud valve 30,or because of interruptiion or loss of the mud circulation,-the pilotgate |90 will at once indicate the cessation of flow and conversely alsothe resumption of flow.

When the drill releases high underground pressures, this usually resultsin diluting the mud uid by gas. The specific gravity valve gate 94 willthen sink and automatically close theoutlet, whereupon the well uid willseek escape at the axial outlet of casing valve 25 which contains theblowout preventer 26 and the kelly 21h The rising fluid will carry thepreventer plug firmly. into its tapered seat in shell 19. Should thecirculating mud be lost as in large cavities or by inltration or shouldthe mud level be otherwise lowered as when withdrawing the drill string,the valve gate 94 will descend to closing position.

Under certain other conditions of well drilling and in certain oilfields, the bit may release high underground pressures which may resultin unstable equil'brium of the mud column inthe well without sufcientchange of its specific gravity to permit the valve gate 94 to sink. Insuch event upon rise of the uid ow through outlet 92 of the mud valve38, the ilow level valve gate 96 will automatically close the mud valveoutlet with consequent automatic closure of the axialY outlet of casingvalve by the blow out preventer plug 15.

In this embodiment of my invention, the bushing 48 serves as the valveseat and other casing valve purposes. However considering the bushing 48and the several parts secured and contained by it, it is manifest thatthe bushing 48 may be secured into any other kind of casinghead. Therapid, simple operation of inserting and locking the prevcnter 26 intobushing 48 of casing valve 25 or other equivalent casinghead, and itsequally facile removal therefrom, all from the derrick noonmade possibleby my invention-.-eliminates a dangerous hazard to the workers who forother types of preventer devices have been required to do this work atthe casinghead under the derrick floor.

Upon withdrawing the kelly, a split packer for round drill 'pipe similarto that illustrated in my aforesaid co-pending application Serial No.385,- 270 may be inserted in bushing 48 of the casing valve orequivalent casinghead and quickly locked in place by the means providedby my invention.

In the event of unstable fluid conditions as the drill is nallywithdrawn, it is manifest from the previous description that both thecasing Valve' 25 and the mud valve 30 will close automatically therebyranticipating and effectively preventing blowout from the well casing.

Fluid pressure within 'the casing valve is exerted upon the flangecollar 24 and the innermost terminal collar with resultant increase ofpressure and tighter seating of each inner terminal ing the casing's ininterlocking support, namely one part for each string of casing, and theminimum number of possible leakage paths are achieved.

Terminal collars which with their vent heads and vent pipes are disposedat a common level instead of being superimposed, make possible thetermination of the casings at about the ground level thereby eliminatingthe cellar, and enables installing the casinghead equipment in therelatively small space between the ground surface and the dcrrickfloor,-all of which are important contributions to safety for the menand the entire installation, and to greater facility of operation,inspection and maintenance.

Although I have described several specific embodiments of my invention,it will be obvious to those skilled in the art, that variousmodifications may be made in the details of construction, the generalarrangement, the association of the several co-operating parts and theapplication of my invention without departing from the spirit thereof orthe principles herein set forth.

I claim as my invention:

l. A blowout preventer for automatically preventing thc blowout of afluid from a casing head, comprising a valve mechanism having aplurality of pivoted valve gates each independently controlling the flowof fluid therethrough, manually operated means for opening and closingone of said gates, and manually controlled means for admitting fluidunder pressure into the valve mechanism between gates for opening onegate to permit said uid to pass into the well, and for closing the othergate to prevent fluid from escaping from said head.

2. A valve for controlling fluid flow from a well, and a valve gatenormally floating in said fluid, passing through said valve and sinkabletherein upon decrease of the specic gravity of said fluid.

3. In apparatus for preventing `blowout of fluids from a well casinghead, means forming an outlet from said head, and a valve closuremechanism for the outlet, said closure mechanism being so constructedand arranged that it is actuated to close the outlet by any of thefollowing: a decrease in specific gravity of the fluid; an increase inthe pressure thereof; a rise of fluidlevel in the casing.

4. In apparatus for preventing blowout of fluids from a well casinghead, means forming an outlet for fluid from said head, and a valveclosure for the outlet, so constructed and arranged that it is actuatedto close the outlet by a rise of fluid level in the casing.

5. In apparatus for preventing blowout of fluids from a well casinghead, means forming an outlet chamber from said head, said chamber beingbelow the level of fluid at normal operation, and a submerged movableclosure in the chamber for the outlet and having a definite specificgravity so that its position in the chamber is dependent upon thespecific gravity of the fluid.

6. In apparatus for preventing blowout of fluids from a well casinghead, means forming an outlet chamber from said head, said chamber beingbelow the level of fluid at normal operation, means forming a closurefor the outlet, and submerged in the chamber, and a pivotal support for.

the means, said means having a definite specific gravity so that itssubmerged angular position on its pivot depends upon the specificgravity of the fluid.

7. In apparatus for preventing blowout of fluids from a well casinghead, means forming ari outlet chamber from said head, said chamberbeing below the level of fluid at normal operation, and a submergedclosure in the chamber, said closure being pivoted above a seat in thechamber and extending from the pivot toward the inlet side of thechamber, said closure having a definite specific gravity so that itsangular position in the chamber becomes nearer vertical upon a decreasein specific gravity of the fluid, and in position to be acted upon bythe fluid pressure to effect complete closure of the outlet.

8. In apparatus for preventing blow-out of fluids from a well casinghead, means forming an outlet conduit from said head, said conduithaving an opening substantially at normal fluid level, and a movablevalve closure for said opening, said closure being in the path of flowof fluid when the fluid level rises above a definite level higher thanthe lower limit of the opening, whereby said closure is moved by saidfluid to close the opening.

9. A blow-out prcventer for a casing head, comprising means forming afluid outlet from the casing head, a pair of separated valve closuresfor closing the outlet, means for so supporting said closures that fluidpressure in the casing may maintain said closures in closed position,and means intermediate said closures for conducting fluid under pressureinto the head past one closure while causing the other closure to close.

10. A blow-out preventer for a casing head, comprising means forming anupwardly directed fluid outlet from said casing head, a pair of valveclosures in said outlet, one of said closures being in the lower end ofthe outlet, and the other being in the higher end thereof, means forsupporting the lower closure so that it may be maintained in closedposition by pressure inside the casing, means for supporting the upper'closure to be in the path of fluid escaping from the outlet when thefluid level exceeds a definite point, and means for admitting fluidunder pressure between said closures, to open the lower closure for theentry of said fluid, and to close the upper closure.

11. In apparatus for preventing blowout of fluids from a welt casinghead-means forming an outlet from the head, said means providing a pairof valve seats on opposite sides of the end of the outlet, a pair ofclosures coacting respectively with said seats, and means forming acommon pivot above the seats, for both closures.

l2. In apparatus for preventing blowout of fluids from a well casinghead, means forming an outlet from the head, saidmeans providing a pairof valve seats on opposite sides of the end of the outlet, a pair ofclosures coacting respectively with said seats, means forming a commonpivot above the seats, for both closures, and means whereby openingmovement of the outer closure assists the closing movement of the innerclosure.

13. In apparatus for preventing the blowout of fluid from a casing head,having an outlet, a valve mechanism in the outlet for controlling it,said valve mechanism including means for closing the outlet, actuated bya reduction in the specific gravity of said fluid below a desiredminimum value, or by an increase in pressure thereof, above a desiredmaximum value.

14. In apparatus for preventing blow-out of fluids from a well casinghead, means forming a fluid outlet from said head, and a valve mechanismfor controlling said outlet, said mechanism including a member actuatedin response to variations in specific gravity of the fluid and moved tocause the Valve mechanism to close upon a reduction in the specicgravity below a desired minimum value.

15. In apparatus for preventing blow-out of fluids from a well casinghead, means forming an outlet from said head, and a Valve closuremechanism for controlling said outlet, said valve closure mechanismincluding a member normally oating in uid passing through the Valvemechanism and acting in response t0 a reduction in the specic gravity ofthe uid below a desired value, to cause the outlet to close.

FREDERIC W. HILD.

